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Diesel or Petrol?

What is Euro 6?

Euro 6 is the sixth incarnation of stringent European emission standards which define the acceptable limits for exhaust emissions of new vehicles sold in EU member states. The current legal standard since September 2014 is Euro Stage 6.

Petrol and diesel cars produce different types of emissions and are subject to different restrictions under the Euro 6 legislation. The permitted level of NOx for diesel cars is 0.08g/km while the permitted level for petrol cars is 0.06g/km.

Our ground-breaking new SKYACTIV-D Diesel and SKYACTIV-G petrol engines, available across the entire Mazda range exceed Euro Stage 6 emissions standards. All new Mazda models also comply with Ultra Low Emission Zone (ULEZ) requirements.

Mazda diesel cars and the Euro 6 emissions standards

As the World’s lowest compression ratio diesel, our SKYACTIV-D diesel engines are fully compliant with all Euro6 standards without the aid of expensive NOx (nitrogen oxide) after treatment systems such as AdBlue, offering clean and efficient engines that are designed to offer you the right engine for your needs without compromise. This delivers on our promise of cars that are fun to drive and meets our commitment to protecting the environment.

Our innovative SKYACTIV diesel technology has a compression ratio much lower than traditional diesels; this allows the combustion temperature and pressure at the optimal moment to be lower, extending ignition so the air and fuel has time to mix much better, making combustion more uniform and complete. The more complete the combustion, the less CO2, and NOx is produced.

Frequently asked questions

Should you consider Diesel?

Diesel remains the right choice for high mileage drivers and people who regularly tow loads. Diesel also emits 20% less CO2 than the equivalent petrol engine and typically uses 20% less fuel.

Diesel engines have been the fuel of choice for many years in the UK. However, recent controversy around diesel emissions has led to some misleading and confusing headlines. So what are the facts?

A rise in the awareness of the harm caused by nitrogen oxide (NOx) has more recently caused concern. Euro6 emission standard requires Diesels to produce below 0.08g/km of nitrogen dioxide which is, an 86% reduction verses standards at the beginning of the decade and all Mazda engines exceed this requirement.

Are manufacturers doing anything to combat NOx emissions?

Diesel emissions have been in the spotlight since 1992, when European standards were introduced to gradually reduce their harmful effects. The current standard, known as Euro 6 was introduced in September 2014, and reduced acceptable NOx emissions to just 0.08g/km.

Conscientious manufacturers like Mazda have been working on emissions compliance for a long time, and in fact, our SKYACTIV-D engines complied with Euro 6 emissions restrictions as early as 2013, two years before the standard was even introduced.

This is reflected and recognised by government policy. When the London Ultra Low Emission Zone is introduced in 2019, Euro 6 compliant vehicles will be able to enter the zone free of charge.

Whereas some manufacturers have introduced engines that combine a ‘NOx trap’ and technology that adds a liquid treatment (called AdBlue) to convert NOx into nitrogen and water, Mazda diesel engines currently (correct as at 2017) do not, as our latest SKYACTIV-D engines are naturally super-efficient, just as they are.

Okay, so what makes SKYACTIV-D engines so great?

Mazda’s SKYACTIV-D technology reduces the fuel compression ratio much lower than traditional diesel engines. In fact, at 14:1, it’s the lowest in the world. Put simply, that means that the temperature and pressure at which the fuel will optimally work is also much lower.

For the price of a longer ignition time of just half a millisecond, the air and fuel gets longer to mix together properly, resulting in much more uniform and efficient combustion. And that means the CO2 and NOx emissions are also reduced as part of the process.

So, diesel is still a good choice then?

If you regularly drive long distances or tow, diesel is still going to be your most efficient and economical choice. According to the SMMT (Society of Motor Manufacturers and Traders), diesel drivers on average cover 60% more miles than those opting for petrol, so those lower fuel bills will make a difference. And the naturally higher torque a diesel engine delivers makes them great for towing or carrying heavier loads.

So, while traditional diesels do produce more harmful polluting emissions, and some manufacturers have had to integrate costly and time-consuming technology to counter their effects, Mazda’s SKYACTIV-D engines pass the strictest of standards (Euro6) with ease. If your lifestyle demands a diesel, you can be assured that our engines have been developed to exceed current emission standards, including CO2 and NOx.